1. Field of the Invention
The present invention relates to an organic light emitting display device and a manufacturing method thereof, and more particularly, to an organic light emitting display device wherein organic and inorganic films are alternately stacked, and the inorganic film is patterned to form an outgassing route, through which gas is released from the organic film, and a manufacturing method thereof.
2. Discussion of the Related Art
An image display device realizing various kinds of information through a screen, which is a core technology in information communication, has been developed such that the image display device is thinner, lighter, portable, and high-performance. An organic light emitting display device that controls the amount of light emitted from an organic light emitting layer to display an image has been spotlighted as a flat panel display device, the weight and volume of which are less than those of a cathode ray tube.
The organic light emitting display device is a self emitting device using a thin light emitting layer between electrodes and has an advantage in that the organic light emitting display device can be thinned like paper. The organic light emitting display device may be classified as an active matrix type organic light emitting display device that can be selectively driven by a cell drive unit of each pixel or a passive matrix type organic light emitting display device that can be controlled for each line.
In the active matrix type organic light emitting display device (AMOLED), pixels expressing three colors (R, G, and B) are arranged in a matrix pattern to display a picture. Each pixel includes an organic light emitting diode (OLED) and a cell drive unit to drive the organic light emitting diode. The cell drive unit, including at least two thin film transistors connected between a gate line to supply a scan signal, a data line to supply a video data signal, and a common power line to supply a common power signal, drive an anode of the organic light emitting diode.
The organic light emitting diode includes an anode, hole injection layer (HIL), hole transport layer (HTL), light emitting layer, electron transport layer (ETL), electron injection layer (EIL), and a cathode.
Meanwhile, the organic light emitting display device is configured by depositing an inorganic insulating film to protect a thin film transistor array, an organic planarization film to planarize the inorganic insulating film, and an inorganic insulating film to stabilize the surface before formation of the organic light emitting diode or having an optical compensation function. During driving of the organic light emitting display device for a long period of time, outgassing occurs from the organic film between the inorganic insulating films.
When gas remains in the organic film, however, the diode is deteriorated with the result that a shrinkage phenomenon, in which the size of each pixel is reduced, is accelerated, which may fatally affect the lifespan of the diode.
The conventional organic light emitting display device as described above has the following problems.
In the structure in which the organic and inorganic films are alternately stacked, tight contact at the interface between the organic and inorganic films is low with the result that outgassing may occur in the organic film during reliability testing or driving for a long period of time.
During outgassing, gas may remain in the organic film to deteriorate the diode and to accelerate a shrinkage phenomenon in which the size of the diode is reduced over time, by which the lifespan of the diode is greatly reduced.